There exist in the U.S. patent literature a substantial collection of patents relating to apparatus and techniques for treatment of spinal disorders. The following U.S. patents are believed to represent the state of the art: U.S. Pat. Nos. D377,527; D377,096; D377,0955; 5,772,661; 5,766,254; 5,755,732; 5,741,261; 5,741,253; 5,735,899; 5,735,852; 5,733,284; 5,730,706; 5,728,127; 5,728,098; 5,728,097; 5,725,582; 5,720,751; 5,720,748; 5,718,877; 5,718,240; 5,716,415; 5,716,357; 5,704,936; 5,702,455, 5,702,449; 5,702,395; 5,702,393; 5,700,292; 5,700,291; 5,700,239; 5,697,929; 5,697,889; 5,690,629; 5,688,274; 5,688,273; 5,688,272; 5,683,464; 5,683,390; 5,676,703; 5,676,701; 5,676,665; 5,675,850; 5,674,296; 5,674,295; 5,672,175; 5,669,909; 5,667,506; 5,665,122; 5,662,686; 5,658,335; 5,653,708; 5,651,789; 5,649,945; 5,647,872; 5,645,598; 5,645,084; 5,643,329; 5,643,263; 5,643,262; 5,643,260; 5,643,259; 5,634,925; 5,634,891; 5,630,816; 5,630,802; 5,624,442; 5,624,441; 5,620,458; 5,618,315; 5,611,800; 5,609,636; 5,609,635; 5,609,592; 5,599,287; 5,599,279; 5,593,409; 5,593,407; 5,591,235; 5,591,165; 5,584,831; 5,571,102; 5,562,736; 5,562,663; 5,562,662; 5,558,674; 5,556,428; 5,549,607; 5,545,166; 5,545,163; 5,540,690; 5,536,268; 5,534,030; 5,534,002; 5,531,745; 5,527,314; 5,522,899; 5,520,690; 5,520,687; 5,505,732; 5,499,983; 5,498,263; 5,498,262; 5,498,233; 5,496,281; 5,489,308; 5,476,464; 5,476,463; 5,476,462; 5,474,555; 5,454,551; 5,458,638; 5,454,812; 5,443,514; 5,439,463; 5,437,669; 5,415,661; 5,415,659; 5,413,576; 5,403,314; 5,390,683; 5,383,884; 5,363,841; 5,314,432; 5,306,309; 5,306,307; 5,306,275; 5,282,862; 5,279,310; 5,267,999; 5,261,913; 5,261,912; 5,261,910; 5,258,019; 5,209,751; 5,112,332; 5,090,758; 5,059,193; 4,854,304; 4,836,196; 4,759,769; 4,714,469; 4,686,970; 4,573,454; 4,445,513; 4,401,112; 4,085,744; 4,047,524; 4,041,939.
The current state of the art relating to lumbar disc surgery is described in Current and Future Approaches to Lumbar Disc Surgery (A Literature Review) By C. H. Alleyne Jr. and G. E. Rodts Jr. Medscape Orthopedics & Sports Medicine which appears on the Internet on http://www.medscape.coni/Medscape/OrthoSportsMed/1997/v01.n11;mos30518/07/98mos3, as well as in the references cited therein. The disclosures of all patent and literature references, mentioned in this Background of the Invention section, are hereby incorporated by reference.